A couple of years ago we got a call from the school saying that my daughter's locker was identified by the drug dogs as one with something in it. She got taken to the office and they interviewed her about what was in a cloth bag that was found in the locker.
It turned out to be a cloth toy she had made for her friend's cat. It was filled with catnip.
It was kind of shocking, but funny too. That was the end of this incident.